STEP AP203/AP214 File Exchange

Application Protocols (APs) are used to exchange data. Each AP pertains to a different application area. For example, AP227 pertains to spatial plant technology and contains several entities pertaining to that area, such as pipe or elbows. Also, these APs use certain common entities known as generic resources, such as geometry and topology, to define solid models.

AP203 applies to representations of mechanical parts and assemblies. AP214 applies to representations of data relating to automotive design. Present day AP203 files typically contains the boundary representation model, assembly data, and a limited amount of other product information. AP214 files typically contain colors, layers, and generic resources.

The boundary representation of a model is a CAD model represented by its boundary. For example, a surface model consists of only the surfaces use to make the model. Solid models include geometry information, such as surfaces, curves, and points, and topology information, such as edges, vertices, and faces. The geometry information provides data about the form of the model, and the topology information provides the connectivity between these geometric elements and the extent of the geometric elements.